Centrifugal separator Combination

Mothes-Loffier All centrifugal separators. Combines migration to wall with interchange between inner and outer part of the vortex. Based on concept introduced by Dietz... 

Mechanical Centrifugal Separators A number of collectors in which the centrifugal field is supphed by a rotating member are commercially available. In the typical unit shown in Fig. 17-45, the exhauster or fan and dust collector are combined as a single unit. The blades are especially shaped to direct the separated dust into an annular slot leading to the collec tion hopper while the cleaned gas continues to the scroll. 

The centrifugal separation of solid impurities is adopted either as an alternative to filtration or combined with it. For example, having fixed-element filters that arrest larger particles, and a centrifuge system that removes the finer solids in suspension together with any water contained in the oil can clean a lubricant circulating system. 

Hydraulic characteristics, 180 Performance curves, 180-182 Centrifugal separator, 256, 257 Combination, 257... 

Drain the aqueous acetonitrile (lower) phase into a 500-mL round-bottom flask, and save the separatory funnel for extraction. Extract the hexane-fat mixture by transferring the mixture back to the polypropylene centrifuge bottle and adding 100 mL of acetonitrile-water (4 1, v/v) solution. Balance the duplicate centrifuge bottles, and cap and shake the bottles for 10 min on the shaker. Centrifuge the second extract at 11 000 rpm for 15 min. Decant this second extract into the 250-mL separatory funnel as before. After phase separation, combine the aqueous extracts in the 500-mL round-bottom flask, and discard the top hexane-fat layer. Add 10 drops of Dow Coming Antifoam B emulsion and 3 mL of 10% aqueous Igepal CO-660 (nonionic surfactant) to the flask. 

The reaction mixture was then extracted twice with diisopropylether (2 x 150mL). (If problems with the phase separation of the reaction mixture occur, then it should be centrifuged.) The combined solutions were dried with sodium sulfate and the organic solvent was removed under reduced pressure. 

Separate yolks of chicken eggs from egg white and discard egg white. Wash the yolks carefully with water to remove adhering egg white. Suspend the yolks in 5 vol. Soln. A by vigorous stirring. Precipitate lipids and lipoproteins by addition of 6 ml Soln. B and 15 ml Soln. C per 100 ml yolk suspension. Stir at RT for 30-60 min and spin at 5000 x g for 10 min. Wash the pellet with a small volume of Soln. A (about 20 ml per yolk) and centrifuge again. Combine the supernatants and filter through a paper filter. Add Soln. D to the clear filtrate to a final concentration of 30 mM EDTA. 

Dekker et al. [170] have also shown that the steady state experimental data of the extraction and the observed dynamic behavior of the extraction are in good agreement with the model predictions. This model offers the opportunity to predict the effect of changes, both in the process conditions (effect of residence time and mass transfer coefficient) and in the composition of the aqueous and reverse micellar phase (effect of inactivation rate constant and distribution coefficient) on the extraction efficiency. A shorter residence time in the extractors, in combination with an increase in mass transfer rate, will give improvement in the yield of active enzyme in the second aqueous phase and will further reduce the surfactant loss. They have suggested that the use of centrifugal separators or extractors might be valuable in this respect. 

Adopting 60-mm [2.4-in.] cyclones, which operate at lower spin speeds for the same flow rate, resulted in smaller centrifugal separation forces. This probably results in a less dense central core, which requires a higher reject ratio to allow complete oil removal. Additionally, the TLP crude exhibits a high tendency to foam, which, when combined with the flash gas that exists preferentially in the reject stream, creates a foamy gassy mixture. This in effect reduces the Vortoil capacity because the flow rate needs to be limited to reduce Ato ensure that sufficient driving force exists. 

To methyl 2-chloro-2-[l-(dibenzylamino)cyclopropyl]acetate (710 mg, 2.06 mmol) in THF (15mL) and HjO (190 pL) an excess of freshly prepared Zn/Cu couple was added, and the resulting mixture was kept in an ultrasonic bath at rt for 18 h and then at 65"C for 8 h. The solid components of the mixture were separated in a centrifuge and washed with CHCI3 (10 mL) followed by threefold centrifugation. The combined hquid organic phases were concentrated in vacuo, and the residue was chromatographed on silica gel (60 g, 2.6 X 37 cm, petroleum ether/EtjO 9 1) yield 414 mg (65%) colorless oil. 

It should be pointed out that combiantions of the above three separation types are frequently found. Extractive and azeotropic distillation, in which a mass separating agent is added to enhance or make feasible a particular separation, are two examples. A recent invention in which distillation and centrifugation are combined to improve the separation potential of otdinaty distillation is aanther example.3... 

Combination of drives. In an actual centrifuge driven by a motor at the bottom, motor inefficiency introduces heat at the bottom end cap. The longitudinal variation of circulation rate then depends on where this heat is removed and whether other heat sources are present. Examples of centrifuge separation performance will be given for two cases ... 

Centrifugal separators are applied in industry for the recovery of microbial cells from cultivation media. In waste water engineering a combination of flocculation and sedimentation is practiced. In the laboratory, cross-flow membrane separation is often used for retention of the cells. Some microorganisms and cells are enriched in the foam therefore, flotation is suited for the recovery of particular microbial cells from cultivation medium. 

A centrifugal contactor usually involves a combination of a high-speed mixer and centrifugal separator in a single nnit. Several different designs are available from manufacturers such as Robatel, Centrek (Kuznetsov et al. 2002), Westfalia, and Pod-bielniak. Figure 5.25 illustrates the contacting and separation phases. 

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